Engineering
Physics
Center of Mass
Circular Motion in Vertical Plane
Forces and Types of Forces
Question

If the maximum tension the ring can withstand is Fmax and its linear mass density is d. The maximum permissible linear velocity of a rotating thin lead ring (axis of rotation is the axis of the ring) is

FMaxd

FMax3d

FMax2d

2FMaxd

JEE Advance
College PredictorLive

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.

Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA

Solution
Verified BY
Verified by Zigyan

For a thin ring rotating about its axis, the centripetal force is provided by tension. Consider a small element of mass dm. The centripetal force on this element is dm × v²/R. This force is balanced by the tension forces from both sides. For a small angle dθ, the net inward force from tension is 2T sin(dθ/2) ≈ T dθ. Equating forces: T dθ = (d × R dθ) × v²/R, where d is linear mass density. Simplifying: T = d v². Thus maximum velocity occurs when T = Fmax, giving vmax = √(Fmax/d).

Final answer: FMaxd